Method for assembling components on a circuit board

ABSTRACT

A method for assembling components on a circuit board includes driving the circuit board to an assembling position after the circuit board is moved in a first direction and then is blocked at a positioning point by a positioning rod, assembling a first component set on a first region of the circuit board when the circuit board is positioned in the assembling position, folding the positioning rod, driving the circuit board back to the positioning point after the first component set has been assembled on the first region of the circuit board, driving the circuit board in the first direction until the positioning rod moves to an end of a slot on the circuit board, driving the circuit board to the assembling position again, and assembling a second component set on a second region of the circuit board when the circuit board is positioned in the assembling position.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 12/694,293 filedon Jan. 27, 2010, and the entire contents of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for assembling components on acircuit board, and more particularly, to a method for respectivelyassembling components on different regions of a circuit board.

2. Description of the Prior Art

Surface mounting technology is a kind of welding technology utilizedgenerally in recent years, which uses specific tools to position surfacemounting elements on welded printed circuit board or bound printedcircuit board accurately. After welding, fine mechanical connection andelectrical connection can be set up between the elements and the circuitboard. Main process of the conventional surface mounting technology isdivided with solder printing, solder printing detecting, high speedcomponent placement, general component placement, soldering stove,optical detecting, and so on. In current manufacturing process, width ofthe printed circuit board is limited to width of a track (around 460mm), and the width of the track is designed according to minimum widthof equipment. Therefore, the width of the track is invariable withoutadjusting equipment. Length of the printed circuit board is limited todimensions of a platform of a high-speed component placement machine(around 510 mm). That is to say, limitation of the length and the widthof the printed circuit board are 510 mm and 460 mm respectively withconventional process of the surface mounting technology, and it limitsthe possible maximum dimensions of the printed circuit board.

For example, working principle of the conventional high-speed componentplacement machine is conveying the printed circuit board to apositioning point to touch a rod, moving the printed circuit board awayby the high-speed component placement machine after a detector detectsthe printed circuit board, setting components on the printed circuitboard and backing the printed circuit board to the initial place, andconveying the printed circuit board to a next working station by aconveying belt. Due to limitation of the platform of the high-speedcomponent placement machine, the dimensions of the printed circuit boardcan not be manufactured over 510 mm in length and 460 mm in width, dueto the limitation of the component placement machine. Because dimensionsof the component placement platform are fixed, when a setting area ofcomponents is over than the dimensions of the platform, the printedcircuit board can not be manufactured except upgrading new equipments,such as adding extra equipments on the next working station ofproduction lines. However, upgrading the production lines formanufacturing larger dimensions of the printed circuit board spends alot. Due to advanced demands of the printed circuit board of a server,the dimensions of the printed circuit board is expanded continuously,and actual design is limited to manufacturing limitation. Thus, how toovercome the limitation and to enlarge the manufacturing dimensions isan important issue for the printed circuit board industry.

SUMMARY OF THE INVENTION

The present invention provides a method for assembling components on acircuit board for solving above drawbacks.

According to the claimed invention, a method for assembling componentson a circuit board, the method includes forming a slot on the circuitboard, driving the circuit board in a first direction, driving thecircuit board to an assembling position in a second direction differentfrom the first direction after the circuit board is blocked at apositioning point by a positioning rod, wherein a first width of theunadjusted positioning rod is larger than a width of the slot so thatthe unadjusted positioning rod can not pass through the slot, assemblinga first component set on a first region of the circuit board when thecircuit board is positioned in the assembling position, adjusting thepositioning rod to a second width being smaller than the first width,wherein the second width is smaller than the width of the slot, drivingthe circuit board back to the positioning point after assembling thefirst component set on the circuit board, driving the circuit board inthe first direction until the positioning rod reaches an end of theslot, driving the circuit board to the assembling position in the seconddirection when the positioning rod reaches the end of the slot, andassembling a second component set on a second region of the circuitboard when the circuit board is positioned in the assembling position.

According to the claimed invention, forming the slot on the circuitboard includes forming the slot on a side of a cut edge of the circuitboard.

According to the claimed invention, the first direction is perpendicularto the second direction substantially.

According to the claimed invention, assembling the first component seton the first region of the circuit board includes setting the firstcomponent set on the first region of the circuit board with surfacemounting technology.

According to the claimed invention, assembling the first component seton the first region of the circuit board includes setting the firstcomponent set on the first region of the circuit board by a componentplacement machine.

According to the claimed invention, adjusting the positioning rod to thesecond width being smaller than the first width includes rotating twopivoting components of the positioning rod relative to a shaft so as tofold the positioning rod to the second width being smaller than thefirst width.

According to the claimed invention, rotating the two pivoting componentsof the positioning rod relative to the shaft includes rotating the twopivoting components of the positioning rod relative to the shaft to thefirst direction.

According to the claimed invention, the method further includesretrieving the positioning rod after the positioning rod reaches the endof the slot.

According to the claimed invention, assembling the second component seton the second region of the circuit board includes setting the secondcomponent set on the second region of the circuit board with surfacemounting technology.

According to the claimed invention, assembling the second component seton the second region of the circuit board includes setting the secondcomponent set on the second region of the circuit board by a componentplacement machine.

According to the claimed invention, the method further includesdetecting whether the circuit board is positioned correctly.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of a circuit board assemblingsystem according to a preferred embodiment of the present invention.

FIG. 2 is a flow chart of assembling the components on a circuit boardaccording to the preferred embodiment of the present invention.

FIG. 3 is a diagram of the circuit board according to the preferredembodiment of the present invention.

FIG. 4 is a diagram of a positioning rod of the circuit board assemblingsystem according to the preferred embodiment of the present invention.

FIG. 5 to FIG. 12 are diagrams of assembling the components on thecircuit board according to the preferred embodiment of the presentinvention.

DETAILED DESCRIPTION

Please refer to FIG. 1. FIG. 1 is a functional block diagram of acircuit board assembling system 50 according to a preferred embodimentof the present invention. The circuit board assembling system 50includes a circuit board 52, which can be a printed circuit board. Thecircuit board 52 includes a first region 521 and a second region 522.The circuit board assembling system 50 further includes a componentplacement machine 54 for assembling components on the circuit board 52.The component placement machine 54 can respectively set a firstcomponent set 56 and a second component set 58 on the first region 521and the second region 522 of the circuit board 52 with surface mountingtechnology. The component placement machine 54 can be a high-speedcomponent placement machine or a general component placement machine.The circuit board assembling system 50 further includes a conveyingdevice 60 for conveying the circuit board 52 to a positioning point andfor conveying the circuit board 52 between the positioning point and anassembling position of the component placement machine 54. The conveyingdevice 60 can be a conveying belt mechanism. The circuit boardassembling system 50 further includes a detecting unit 62 for detectingwhether the circuit board 52 is positioned correctly. The detecting unit62 can be an optical sensor. The circuit board assembling system 50further includes a control unit 64 for controlling the conveying device60 to drive the circuit board 52 to the assembling position after thedetecting unit 62 detects the circuit board 52 is positioned correctly,for controlling the component placement machine 54 to assemble the firstcomponent set 56 on the first region 521 of the circuit board 52, forcontrolling the conveying device 60 to drive the circuit board 52 backto the positioning point after the first component set 56 is assembledon the circuit board 52, and for controlling the conveying device 60 todrive the circuit board 52 to the assembling position and controllingthe component placement machine 54 to assemble the second component set58 on the second region 522 of the circuit board 52. Detailedoperational principle of the circuit board assembling system 50 isintroduced as follows.

Please refer to FIG. 1 to FIG. 4. FIG. 2 is a flow chart of assemblingthe components on the circuit board 52 according to the preferredembodiment of the present invention. FIG. 3 is a diagram of the circuitboard 52 according to the preferred embodiment of the present invention.FIG. 4 is a diagram of a positioning rod 66 of the circuit boardassembling system 50 according to the preferred embodiment of thepresent invention. A method for assembling the components on the circuitboard 52 includes following steps:

Step 100: Form a slot 524 on a side of a cut edge 523 of the circuitboard 52;

Step 102: The control unit 64 controls the conveying device 60 to drivethe circuit board 52 to the positioning point in a first direction;

Step 104: When the circuit board 52 is blocked at the positioning pointby the positioning rod 66, the detecting unit 62 detects whether thecircuit board 52 is positioned correctly. A first width W1 of theunadjusted positioning rod 66 is larger than a width W3 of the slot 524so that the unadjusted positioning rod 66 can not pass through the slot524;

Step 106: The control unit 64 controls the conveying device 60 to drivethe circuit board 52 to the assembling position in a second directiondifferent from the first direction after the circuit board 52 ispositioned correctly;

Step 108: When the circuit board 52 is in the assembling position, thecontrol unit 64 controls the component placement machine 54 to assemblethe first component set 56 on the first region 521 of the circuit board52;

Step 110: Fold the positioning rod 66 to a second width W2 smaller thanthe first width W1. The second width W2 is smaller than the width W3 ofthe slot 524;

Step 112: The control unit 64 controls the conveying device 60 to drivethe circuit board 52 back to the positioning point after the componentplacement machine 54 assembles the first component set 56 on the firstregion 521 of the circuit board 52;

Step 114: The control unit 64 controls the conveying device 60 to drivethe circuit board 52 in the first direction until the positioning rod 66reaches an end of the slot 524;

Step 116: When the positioning rod 66 reaches the end of the slot 524,the detecting unit 62 detects whether the circuit board 52 is positionedcorrectly;

Step 118: Retrieve the positioning rod 66 after the circuit board 52 ispositioned correctly and the control unit 64 controls the conveyingdevice 60 to drive the circuit board 52 to the assembling position inthe second direction;

Step 120: When the circuit board 52 is in the assembling position, thecontrol unit 64 controls the component placement machine 54 to assemblethe second component set 58 on the second region 522 of the circuitboard 52; and

Step 122: After the component placement machine 54 assembles the secondcomponent set 58 on the second region 522 of the circuit board 52, thecontrol unit 64 controls the conveying device 60 to drive the circuitboard 52 back to the positioning point and to drive the circuit board 52to a next working station.

Please refer to FIG. 1 and FIG. 5 to FIG. 12. FIG. 5 to FIG. 12 arediagrams of assembling the components on the circuit board 52 accordingto the preferred embodiment of the present invention. First, in step100, the slot 524 is formed on an inner side of the cut edge 523 of thecircuit board 52 shown in FIG. 3. The cut edge 523 of the circuit board52 is the position where a track of the conveying device 60 clips thecircuit board 52, and the cut edge 523 is cut off after the circuitboard 52 is made-up. In step 102, the circuit board 52 processed withsolder printing and solder printing detection moves toward the componentplacement machine 54. As shown in FIG. 5, the control unit 64 controlsthe conveying device 60 to drive the circuit board 52 to the positioningpoint where the positioning rod 66 is positioned in the first direction(X direction). In step 104, because the first width W1 of the unadjustedpositioning rod 66 is larger than the width W3 of the slot 524, thecircuit board 52 is blocked at the positioning point by the positioningrod 66 so that the positioning rod 66 can not pass through the slot 524.As this time, the detecting unit 62 detects whether the circuit board 52is the right one and whether the circuit board 52 is positionedcorrectly. The detecting unit 62 can be operated selectively, whichmeans this detecting process can be omitted. In step 106, the detectingunit 62 detects the circuit board 52 is positioned correctly and outputsa corresponding detecting signal to the control unit 64. After thecontrol unit 64 determines the circuit board 52 is the right one and ispositioned correctly, as shown in FIG. 6, the control unit 64 controlsthe conveying device 60 to drive the circuit board 52 to the assemblingposition where the component placement machine 54 sets the components onin the second direction (+Y direction) different from the firstdirection. The first direction can be perpendicular to the seconddirection substantially. As shown in FIG. 7, in step 108, when thecircuit board 52 is positioned in the assembling position, the componentplacement machine 54 detects at least one optical positioning point 525on the circuit board 52 so as to position the setting positionaccurately. Then, the control unit 64 controls the component placementmachine 54 to assemble the first component set 56 on the first region521 of the circuit board 52, so that a first phase of the settingprocess of the circuit board 52 is completed.

Meanwhile, in step 110, the positioning rod 66 is fold from the firstwidth W1 to the second width W2 smaller than the first width W1. Thesecond width W2 is smaller than the width W3 of the slot 524. One offolding methods of the positioning rod 66 is shown in FIG. 4. Thepositioning rod 66 can include two pivoting components 661 pivoting toeach other for rotating relative to a shaft 662, such as rotating to thefirst direction relative to the shaft 662, so that the foldedpositioning rod 66 can recede a few distance toward the first directionrelative to the original positioning point to avoid interferencegenerated by the circuit board 52 not being positioned on thepositioning point correctly due to assembly tolerance. For example, thewidth W3 of the slot 524 can be 8 mm, the original width (the firstwidth W1) of the positioning rod 66 can be 12 mm, and the originalthickness of the positioning rod 66 can be 2 mm. A tolerance of 4 mmbetween the first width W1 and the width W3 of the slot 524 is reserved.The width of the folded positioning rod 66 is 4 mm (the second widthW2). Therefore, the tolerance of 4 mm is also reserved between the widthW3 of the slot 524 and the second width W2 for ensuring stablemanufacture with high precise tolerance of the track. In addition, thefolded positioning rod 66 can recede 2 mm toward the first directionrelative to the original positioning point so as to ensure that thecircuit board 52 is not broken by hitting the positioning rod 66 afterthe circuit board 52 is back to the positioning point. Mechanical designfor adjusting the positioning rod 66 form the first width W1 to thesecond width W2 smaller than the first width W1 is not limited by afolding manner. For example, it can be operated in a retractable manner,the mechanical design capable of adjusting the width of the positioningrod 66 belongs to the scope of the present invention.

As shown in FIG. 8, in step 112, after the component placement machine54 assembles the first component set 56 on the first region 521 of thecircuit board 52, the control unit 64 controls the conveying device 60to drive the circuit board 52 back to the positioning point again in adirection opposite to the second direction (−Y direction). As this time,the folded positioning rod 66 aligns to the slot 524 of the circuitboard 52. As shown in FIG. 9, in step 114, the control unit 64 controlsthe conveying device 60 to drive the circuit board 52 in the firstdirection (+X direction). Because the second width W2 of the foldedpositioning rod 66 is smaller than the width W3 of the slot 524, thecircuit board 52 can not be blocked by the positioning rod 66, and thecircuit board 52 can move toward the first direction (+X direction)continuously until the positioning rod 66 moves to the end of the slot524. The positioning rod 66 is against the end of the slot 524 of thecircuit board 52. Meanwhile, the detecting unit 62 can detect whetherthe circuit board 52 exists and whether the circuit board 52 ispositioned correctly. The detecting unit 62 can be operated selectively,which means the detecting process can be omitted.

Similarly with the above-mentioned operational principle, in step 118,the detecting unit 62 detects the circuit board 52 is positionedcorrectly and outputs the corresponding detecting signal to the controlunit 64. After the control unit 64 determines the circuit board 52 ispositioned correctly, as shown in FIG. 10, the positioning rod 66 isretrieved, and the control unit 64 controls the conveying device 60 todrive the circuit board 52 to the assembling position where thecomponent placement machine 54 sets the components on in the seconddirection (+Y direction). Method of retrieving the positioning rod 66can be moving the positioning rod 66 away from the slot 524, or candesign a retractable mechanism for retracting the positioning rod 66.The present invention also can replace the mechanism of retrieving thepositioning rod 66 by moving the circuit board 52 away to a positionwithout interfering with the positioning rod 66 so as to drive thecircuit board 52 to the assembling position successfully. As shown inFIG. 11, in step 120, when the circuit board 52 is positioned on theassembling position, the component placement machine 54 can detect theoptical positioning point 525 on the circuit board 52 so as to positionthe setting position accurately. Then, the control unit 64 controls thecomponent placement machine 54 to assemble the second component set 58on the second region 522 of the circuit board 52, so that a second phaseof the setting process of the circuit board 52 is completed. As shown inFIG. 12, in step 122, after the component placement machine 54 assemblesthe second component set 58 on the second region 522 of the circuitboard 52, the control unit 64 controls the conveying device 60 to drivethe circuit board 52 back to the positioning point again in thedirection opposite to the second direction (−Y direction) and to drivethe circuit board 52 to the next working station, so the setting processof the circuit board 52 is fully completed. For assembling the nextcircuit board, the process from step 100 to step 122 can be repeatedcontinuously so as to achieve a purpose of automatically executingsurface mounting process on the circuit boards with large dimensions.

In conclusion, the present invention merely utilizes one componentplacement machine to execute two phases setting process. Therefore, thepresent invention can overcome limitation of the conventional equipmentfor manufacturing the circuit boards with large dimensions withoutadding the extra equipment, and can promote utility rate of theequipment, decrease cost of the equipment, and improve manufacturingefficiency. In addition, dimensional limitation can be solved so thatnew products can be manufactured and designed without limitation. Forexample, the same products can be integrated into one circuit board andthe process can speed up. Furthermore, the present invention can furtherdesign an application of multi-phase setting process, which means aplurality of slots can be disposed on the circuit board and themulti-phase setting process can be executed on the same circuit board.The operational principle is the same as the above-mentioned embodimentand detailed description is omitted herein for simplicity.

Comparing to the prior art, the circuit board assembling technology ofthe present invention can overcome the limitation of the conventionalequipment and can manufacture the circuit board with large dimensionswithout adding the extra equipment so as to promote the utility rate ofthe equipment, to decrease the cost of the equipment, and to improve themanufacturing efficiency.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention.

What is claimed is:
 1. A method for assembling a first component set anda second component set onto a circuit board, the method comprising:forming a slot in the circuit board; driving the circuit board in afirst direction; driving the circuit board to an assembling position ina second direction different from the first direction after the circuitboard is blocked at a positioning point by a positioning rod, wherein afirst width of the unadjusted positioning rod is larger than a width ofthe slot so that the unadjusted positioning rod can not pass through theslot; assembling the first component set on a first region of thecircuit board when the circuit board is positioned in the assemblingposition; adjusting the positioning rod to a second width being smallerthan the first width, wherein the second width is smaller than the widthof the slot; driving the circuit board back to the positioning pointafter assembling the first component set on the circuit board; drivingthe circuit board in the first direction until the positioning rodreaches an end of the slot; driving the circuit board to the assemblingposition in the second direction when the positioning rod reaches theend of the slot; and assembling the second component set on a secondregion of the circuit board when the circuit board is positioned in theassembling position.
 2. The method of claim 1, wherein forming the slotin the circuit board comprises forming the slot in a side of a cut edgeof the circuit board.
 3. The method of claim 1, wherein the firstdirection is perpendicular to the second direction substantially.
 4. Themethod of claim 1, wherein assembling the first component set on thefirst region of the circuit board comprises setting the first componentset on the first region of the circuit board with surface mountingtechnology (SMT).
 5. The method of claim 1, wherein assembling the firstcomponent set on the first region of the circuit board comprises settingthe first component set on the first region of the circuit board by acomponent placement machine.
 6. The method of claim 1, wherein adjustingthe positioning rod to the second width being smaller than the firstwidth comprises rotating two pivoting components of the positioning rodrelative to a shaft so as to fold the positioning rod to the secondwidth being smaller than the first width.
 7. The method of claim 6,wherein rotating the two pivoting components of the positioning rodrelative to the shaft comprises rotating the two pivoting components ofthe positioning rod relative to the shaft to the first direction.
 8. Themethod of claim 1 further comprising: retrieving the positioning rodafter the positioning rod reaches the end of the slot.
 9. The method ofclaim 1, wherein assembling the second component set on the secondregion of the circuit board comprises setting the second component seton the second region of the circuit board with surface mountingtechnology.
 10. The method of claim 1, wherein assembling the secondcomponent set on the second region of the circuit board comprisessetting the second component set on the second region of the circuitboard by a component placement machine.
 11. The method of claim 1further comprising: detecting whether the circuit board is positionedcorrectly.